The funds awarded to iCOMAT under the European Space Agency's General Support Technology Programme (GSTP) will allow iCOMAT to manufacture a novel launch vehicle structure, which will be evaluated and structurally tested in the Bristol Composites Institute laboratories. The goal of the project is to demonstrate the feasibility of using CTS-manufactured composite structures on primary space structures and help to advance the Technology Readiness Level of the CTS technology.
The cylindrical structures used in launch vehicles for space are subjected to excessive compressive forces due to the weight of the rocket's upper stages and due to vertical acceleration during take-off. As a result, a dominant failure mode for these vehicles is buckling, where the cylindrical structure collapses in the same manner that drinks cans do when we step on them. One of the most challenging aspects for engineers is that the load at which buckling occurs is very sensitive to manufacturing imperfections or load eccentricities, often causing premature buckling at 20-30% of the load that would be expected from a "perfect" cylinder.
One of the ways that this imperfection sensitivity can be reduced is by using novel material architectures. The Bristol Composites Institute has previously pioneered the Continuous Tow Shearing (CTS) process, which allows for defect-free manufacture of fibre-reinforced plastics with curved, rather than straight, fibre paths. This research led to the spin-out of company iCOMAT Ltd. in 2019.
Over the last decade, the structural benefits of tow-steered composites have also been demonstrated for many aerospace structures by Prof. Paul Weaver's lightweight structures research group in the Bristol Composites Institute. Recent numerical optimisation work by CDT PhD student Reece Lincoln, supervised by Dr. Rainer Groh, Dr. Alberto Pirrera and Prof. Paul Weaver, has shown that tow-steered composites can reduced the imperfection sensitivity of cylindrical launch vehicle structures and therefore increase the load at which buckling collapse occurs.
Dr. BC Eric Kim, the inventor of the CTS technology and the Chief Technology Advisor of iCOMAT Ltd., said: "This project will be an excellent opportunity to demonstrate the potential of the CTS technology for space application where the structural efficiency is the most critical among different industries. The CTS will allow for best use of fibre-reinforced composites beyond the conventional straight fibre space structures."
Evangelos Zympeloudis, the CEO of iCOMAT Ltd., commented: "We are honoured to have been awarded this contract from the European Space Agency and the UK Space Agency to validate the performance benefits of our novel manufacturing process on fibre steered structures. We are also very keen to work with Dr. Rainer Groh and his team at the Bristol Composites Institute in yet another project."
Dr. Rainer Groh added: "The entire project team is honoured to be part of this European Space Agency mission, carried out by one of the Bristol Composites Institute spinout companies, iCOMAT Ltd. We hope that the project will demonstrate the great potential of using tow-steered composites for lightweight launch vehicle structures and pave the way for other applications of the CTS technology in the space sector."
Please note that the views expressed herein can in no way be taken to reflect the official opinion of the European Space Agency.